CppTools: Cancel parsing if editor is closed

The m_parserFuture.cancel() in ~BuiltinEditorDocumentProcessor() did not
cancel anything. Thus, closing a document while the parser was running
led to a blocking UI thread.

Now it cancels at the next include directive it encounters.

Change-Id: I092fddbbd747e0bc95265b6e9b4fcc26b3f76cb3
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/libs/cplusplus/pp-engine.cpp

@@ -762,6 +762,11 @@ QByteArray Preprocessor::run(const QString &fileName,
     return preprocessed;
 }
 
+void Preprocessor::setCancelChecker(const Preprocessor::CancelChecker &cancelChecker)
+{
+    m_cancelChecker = cancelChecker;
+}
+
 bool Preprocessor::expandFunctionlikeMacros() const
 {
     return m_expandFunctionlikeMacros;
@@ -1636,6 +1641,9 @@ void Preprocessor::handlePreprocessorDirective(PPToken *tk)
 
 void Preprocessor::handleIncludeDirective(PPToken *tk, bool includeNext)
 {
+    if (m_cancelChecker && m_cancelChecker())
+        return;
+
     m_state.m_lexer->setScanAngleStringLiteralTokens(true);
     lex(tk); // consume "include" token
     m_state.m_lexer->setScanAngleStringLiteralTokens(false);

src/libs/cplusplus/pp-engine.h

@@ -56,6 +56,8 @@
 #include <QByteArray>
 #include <QPair>
 
+#include <functional>
+
 namespace CPlusPlus {
 
 class Environment;
@@ -81,6 +83,9 @@ public:
     QByteArray run(const QString &filename, const QByteArray &source,
                    bool noLines = false, bool markGeneratedTokens = true);
 
+    using CancelChecker = std::function<bool()>;
+    void setCancelChecker(const CancelChecker &cancelChecker);
+
     bool expandFunctionlikeMacros() const;
     void setExpandFunctionlikeMacros(bool expandFunctionlikeMacros);
 
@@ -253,6 +258,7 @@ private:
     Client *m_client;
     Environment *m_env;
     QByteArray m_scratchBuffer;
+    CancelChecker m_cancelChecker;
 
     bool m_expandFunctionlikeMacros;
     bool m_keepComments;

src/plugins/clangcodemodel/clangeditordocumentparser.cpp

@@ -35,7 +35,8 @@ ClangEditorDocumentParser::ClangEditorDocumentParser(const QString &filePath)
     setConfiguration(config);
 }
 
-void ClangEditorDocumentParser::updateHelper(const CppTools::WorkingCopy &)
+void ClangEditorDocumentParser::updateHelper(const QFutureInterface<void> &,
+                                             const CppTools::WorkingCopy &)
 {
     State state_ = state();
     state_.projectPart = determineProjectPart(filePath(), configuration(), state_);

src/plugins/clangcodemodel/clangeditordocumentparser.h

@@ -37,7 +37,8 @@ public:
     ClangEditorDocumentParser(const QString &filePath);
 
 private:
-    void updateHelper(const CppTools::WorkingCopy &) override;
+    void updateHelper(const QFutureInterface<void> &future,
+                      const CppTools::WorkingCopy &) override;
 };
 
 } // namespace ClangCodeModel

src/plugins/cpptools/baseeditordocumentparser.cpp

@@ -77,9 +77,16 @@ void BaseEditorDocumentParser::setConfiguration(const Configuration &configurati
 }
 
 void BaseEditorDocumentParser::update(const WorkingCopy &workingCopy)
+{
+    QFutureInterface<void> dummy;
+    update(dummy, workingCopy);
+}
+
+void BaseEditorDocumentParser::update(const QFutureInterface<void> &future,
+                                      const WorkingCopy &workingCopy)
 {
     QMutexLocker locker(&m_updateIsRunning);
-    updateHelper(workingCopy);
+    updateHelper(future, workingCopy);
 }
 
 BaseEditorDocumentParser::State BaseEditorDocumentParser::state() const

src/plugins/cpptools/baseeditordocumentparser.h

@@ -29,6 +29,7 @@
 #include "cppworkingcopy.h"
 #include "projectpart.h"
 
+#include <QFutureInterface>
 #include <QObject>
 #include <QMutex>
 
@@ -39,7 +40,7 @@ class CPPTOOLS_EXPORT BaseEditorDocumentParser : public QObject
     Q_OBJECT
 
 public:
-    using Ptr = QSharedPointer<BaseEditorDocumentParser>;;
+    using Ptr = QSharedPointer<BaseEditorDocumentParser>;
     static Ptr get(const QString &filePath);
 
     struct Configuration {
@@ -58,6 +59,7 @@ public:
     void setConfiguration(const Configuration &configuration);
 
     void update(const WorkingCopy &workingCopy);
+    void update(const QFutureInterface<void> &future, const WorkingCopy &workingCopy);
 
     ProjectPart::Ptr projectPart() const;
 
@@ -76,7 +78,8 @@ protected:
     mutable QMutex m_stateAndConfigurationMutex;
 
 private:
-    virtual void updateHelper(const WorkingCopy &workingCopy) = 0;
+    virtual void updateHelper(const QFutureInterface<void> &future,
+                              const WorkingCopy &workingCopy) = 0;
 
     const QString m_filePath;
     Configuration m_configuration;

src/plugins/cpptools/baseeditordocumentprocessor.cpp

@@ -77,7 +77,7 @@ void BaseEditorDocumentProcessor::runParser(QFutureInterface<void> &future,
         return;
     }
 
-    parser->update(workingCopy);
+    parser->update(future, workingCopy);
     CppToolsBridge::finishedRefreshingSourceFiles({parser->filePath()});
 
     future.setProgressValue(1);

src/plugins/cpptools/builtineditordocumentparser.cpp

@@ -55,7 +55,8 @@ BuiltinEditorDocumentParser::BuiltinEditorDocumentParser(const QString &filePath
     qRegisterMetaType<CPlusPlus::Snapshot>("CPlusPlus::Snapshot");
 }
 
-void BuiltinEditorDocumentParser::updateHelper(const WorkingCopy &theWorkingCopy)
+void BuiltinEditorDocumentParser::updateHelper(const QFutureInterface<void> &future,
+                                               const WorkingCopy &theWorkingCopy)
 {
     if (filePath().isEmpty())
         return;
@@ -181,6 +182,10 @@ void BuiltinEditorDocumentParser::updateHelper(const WorkingCopy &theWorkingCopy
             if (releaseSourceAndAST_)
                 doc->releaseSourceAndAST();
         });
+        sourceProcessor.setCancelChecker([future]() {
+           return future.isCanceled();
+        });
+
         Snapshot globalSnapshot = modelManager->snapshot();
         globalSnapshot.remove(filePath());
         sourceProcessor.setGlobalSnapshot(globalSnapshot);

src/plugins/cpptools/builtineditordocumentparser.h

@@ -58,7 +58,8 @@ public:
     static Ptr get(const QString &filePath);
 
 private:
-    void updateHelper(const WorkingCopy &workingCopy) override;
+    void updateHelper(const QFutureInterface<void> &future,
+                      const WorkingCopy &workingCopy) override;
     void addFileAndDependencies(CPlusPlus::Snapshot *snapshot,
                                 QSet<Utils::FileName> *toRemove,
                                 const Utils::FileName &fileName) const;

src/plugins/cpptools/cppsourceprocessor.cpp

@@ -121,6 +121,11 @@ CppSourceProcessor::CppSourceProcessor(const Snapshot &snapshot, DocumentCallbac
 CppSourceProcessor::~CppSourceProcessor()
 { }
 
+void CppSourceProcessor::setCancelChecker(const CppSourceProcessor::CancelChecker &cancelChecker)
+{
+    m_preprocess.setCancelChecker(cancelChecker);
+}
+
 void CppSourceProcessor::setWorkingCopy(const WorkingCopy &workingCopy)
 { m_workingCopy = workingCopy; }
 

src/plugins/cpptools/cppsourceprocessor.h

@@ -59,6 +59,9 @@ public:
     CppSourceProcessor(const CPlusPlus::Snapshot &snapshot, DocumentCallback documentFinished);
     ~CppSourceProcessor();
 
+    using CancelChecker = std::function<bool()>;
+    void setCancelChecker(const CancelChecker &cancelChecker);
+
     void setWorkingCopy(const CppTools::WorkingCopy &workingCopy);
     void setHeaderPaths(const ProjectPartHeaderPaths &headerPaths);
     void setLanguageFeatures(CPlusPlus::LanguageFeatures languageFeatures);